Fuel Pump Relay Pin (Single Digit) Numbers

Oka · Post by **Oka** » 14 Dec 2019, 21:33

The existing fuel pump relay I removed from my car is a five-pin single digit set of numbers (#s 1,2,3,4, and 5). I am used to the double digit number relays. Could someone please tell me the single digit equivalent to the double digit? I am still searching to get an answer.

Thanks.

Oka · Post by **Oka** » 14 Dec 2019, 21:44

Oka wrote: 14 Dec 2019, 21:33 The existing fuel pump relay I removed from my car is a five-pin single digit set of numbers (#s 1,2,3,4, and 5). I am used to the double digit number relays. Could someone please tell me the single digit equivalent to the double digit? I am still searching to get an answer.

Thanks.

Seconds after posting the above, went back to Googling and I found this site.
https://www.12voltplanet.co.uk/relay-guide.html

Post by **RickHaleParker** » 15 Dec 2019, 01:25

The two digits numbers are DIN Numbers. DIN numbers label the function of the terminal. Single digit numbers are terminal numbers. There is no translation between the two because they are fundamentally different information and therefore not suited to comparison or translation .... like comparing Apples to Oranges.

Post by **abscate** » 15 Dec 2019, 05:21

One is a DIN standard and the other a ISO standard, I don’t remember which is which. I think the 85,86...is DIN since that was on all my old VWs

Ive always wired relays hot signal 85 , ground 86 but have been told the signal works with reversed polarity. I don’t see how the magnet will pull in with opposite current unless switched 87 is bi-directional double pole?

Of course, with a backing diode, you don’t want to reverse polarity for other reasons

Post by **RickHaleParker** » 15 Dec 2019, 22:25

abscate wrote: 15 Dec 2019, 05:21 One is a DIN standard and the other a ISO standard, I don’t remember which is which. I think the 85,86...is DIN since that was on all my old VWs

ISO has a numbering standard for micro relays (Space constraints) that uses one digit markings. The rest are DIN 72552 / European Norm (EN) 50005.

Oka · Post by **Oka** » 21 Dec 2019, 23:08

Oka wrote: 14 Dec 2019, 21:44
Oka wrote: 14 Dec 2019, 21:33 The existing fuel pump relay I removed from my car is a five-pin single digit set of numbers (#s 1,2,3,4, and 5). I am used to the double digit number relays. Could someone please tell me the single digit equivalent to the double digit? I am still searching to get an answer.

Thanks.
Seconds after posting the above, went back to Googling and I found this site.
https://www.12voltplanet.co.uk/relay-guide.html

The corresponding numbers as in the link worked exactly as it should. I tested the relay with my single corresponding number and it worked perfectly.

johntannehill · Post by **johntannehill** » 20 Jan 2026, 16:01

I have the a 5 pin fuel relay and I’m trying to find out which 2 pins slots do I connect to make my fuel pump run continuously the 2 big pins are numbered 3, 5 respectively and the 3 small pins are 2,4,1 respectively. What two pin slots would need to be jumped by a wire to let the fuel pump run continuously? Thanks in advance, John
2005 S40i 2.4 gasoline engine.

Post by **abscate** » 22 Jan 2026, 12:49

If you can find your wiring diagram on the interwebs the relay pin numbers will be referenced on said diagram

johntannehill · Post by **johntannehill** » 22 Jan 2026, 19:04

Abscate, I’ll try looking it up. Thanks hope I can find it.
A Captain, the link sent to a 4 pages of topics & none that I could find answered the question. Could you give me a specific post. Thanks so much to both of you !

Post by **scot850** » 23 Jan 2026, 14:54

Try this link:

viewtopic.php?t=103981

Neil.